arm/dt: msm9625: Add USB OTG and Android devices

Add device tree entries for the USB OTG and Android gadget devices.
Also update device tree documentation to reflect the required
'interrupt-names' property for HSUSB OTG devices.

Change-Id: Ie4f68967c4071d3493b5bbe444b74064209c4173
Signed-off-by: Jack Pham <jackp@codeaurora.org>